For a given power input light output from a light source can vary between that from a relatively small size source (say a light emitting diode) to that from a relatively large size source (say a resistive filament). A relatively high powered sources tend to generate light more efficiently than from a low powered one however high intensity light can dazzle a viewer who perhaps inadvertently views the element directly.
One way to overcome the matter of dazzle is to configure the illumination system so that direct viewing of the illuminated filament cannot occur. However this requirement is not always readily met typically in situations where the envelope available for the illumination system is limited in size.
Another way is to overcome dazzle is to provide an optical filter but this necessarily attenuates the light output so rendering superfluous the use of a relatively high powered source.
However the matter of dazzle is not usually a critical matter in connection with an illumination system. More significant is the degree to which the system can effectively and efficiently illuminate the objects, surface or area involved.